Disease Resilience

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A banana plantation affected by fusarium wilt TR4 (Photo courtesy OECS)

When the Caribbean talks resilience, it’s usually in relation to hurricanes or external economic shocks. What gets less attention, but can be just as destructive, is disease. Whether lobsters infected with a deadly virus, bananas battling highly contagious fungus, or coral reefs decimated by a tissue-eroding disease, the Caribbean is under attack from microscopic organisms that, despite their size, can be devastating to various sectors of the economy.

Tourism under attack

Much of the region’s tourism industry is reliant on its pristine, tropical environment. But when it comes to bothersome bacteria, the delicate ecology of the Caribbean is vulnerable on many fronts.

The beautiful, unique and biodiverse Caribbean coral that brings divers, snorkellers and boaters to the region’s waters is facing a new threat. First recorded in Florida in 2014, Stony Coral Tissue Loss Disease (SCTLD) is now in Caribbean waters, and stripping coral faster than scientists can save reefs. More than 20 species are thought to be at risk of the disease which eats away at coral tissue, leaving it bleached and lifeless. The voracious plague is capable of reducing hundred-year old coral to empty husks within weeks and it has been spreading quickly throughout the Caribbean, impacting reefs in Jamaica, St Maarten, St Thomas, the US Virgin Islands and the Dominican Republic.

Scientists are still unsure about the cause of the disease but theorise that a number of stressors in the environment (bleaching, coastal construction activity, rising water temperatures) may have created ideal conditions for weakened and vulnerable coral to fall victim. Marine biologists across the Caribbean and in Florida are working together to track and remedy the devastating effects of SCTLD, but admit that they are still some way from a cure.

Extinction of coral species on this scale would have long-lasting repercussions for the region’s marine ecology which, in turn, would impact almost all life on land. A loss of coral means a loss of marine habitats. Any resulting dip in fish populations would be significant for the Caribbean’s growing blue economy. 

Agricultural concerns

There’s another resident of the reefs that is falling ill. The Caribbean Spiny Lobster is facing down a nasty virus, which is infecting up to 30% of lobster populations in some areas and putting pressure on the region’s fisheries. 

Panulirus argus virus replaces blood vessels, turning lobsters white before they die from the virus. Contagious and transmittable through water, the virus is persistent and spreads quickly. The pathogen has affected Florida fisheries and experts warn that Caribbean operations will also feel the impact as infected lobsters caught in traps can reduce overall catch and increase transmission within commercial fisheries.

Agriculture in the Caribbean is used to battling disease, and Saint Lucia knows firsthand how a tiny pathogen can send shockwaves through an entire industry. There are two major banana blights affecting Caribbean crops: Black Sigatoka Disease and fusarium wilt. The former, which is also known as banana leaf spot disease, has threatened Saint Lucian production since 2010, affecting around 70% of the island’s banana plants. Given that many farmers lacked the know-how, funds and tools to control the disease, it gained a foothold quickly and has dampened exports in recent years. 

In 2013 the government teamed up with Taiwan, which has also battled Black Sigatoka, to develop disease management techniques, introduce disease-resistant varieties and create a model to combat and control the pathogen going forward. Their efforts in this area have doubled exports and helped the industry return to its pre-Tropical Storm Matthew glory days. Taiwan continues to assist Saint Lucia in safeguarding its bananas, launching a four-year Banana Productivity Improvement Project in 2018 to increase the country’s export competitiveness in the market.

Taiwan was the first country to note another diminutive disruptor – fusarium wilt. This soil-borne fungus enters the banana plant from its roots, destroying the vessels that transport water and nutrients. Tropical Race 4 (TR4), the latest evolution of the lethal fungal disease, affects most varieties of banana and plantain and was first discovered in the 1980s in Taiwan. It has since spread to Asia, the Middle East, Africa and the Americas, leading the OECS to label it a ‘priority pest threatening the region’s banana industry with serious economic, livelihood and food security repercussions’.

In light of the danger, several regional bodies have joined forces to enact surveillance and quarantine procedures. The OECS Agricultural Unit, the Caribbean Plant Health Directors Forum and the Technical Working Group on bananas are all monitoring the situation closely.

Also joining the fray is the UN Food and Agriculture Organization (FAO) which considers TR4 ‘the world’s greatest threat to banana production’ due to its highly contagious nature and the fact that fungicide-resistant spores can lie dormant in soil for more than 30 years. In October the FAO launched an emergency project under its Technical Cooperation Programme to help protect crops, in Latin America and the Caribbean in particular, following the discovery of TR4 in Colombia last summer. The agency will focus on technical assistance in terms of diagnosing and identifying risks, including strengthening soil health and genetic resources to build resilience to the disease in future plants.

Building immunity

When it comes to fending off disease, whether in the body or in a region, the old adage holds true: prevention is better than a cure. But with pathogens able to spread via soil, people, farming tools and water, containment is truly a cross-border effort that requires international and regional partnership on a huge scale. 

Most of Caribbean agriculture and aquaculture consists of small-scale operations, farmers and fishermen who have hands-on knowledge but don’t always have the resources or technical expertise to safeguard their livelihoods. The Caribbean’s immune system relies on funding, public education, awareness and institutional support.